Refrigerant moisture-liquid indicator assembly and cap unit therefor



July 28, 1964 3,142,287

E. JONES REFRIGERANT MOISTURE-LIQUID INDICATOR ASSEMBLY AND CAP UNITTHEREFOR Filed Dec. 22. 1961 2 Sheets-Sheet l 1 NVE N TOR. Egan Jane@July 2s, 1964 E JONES 3,142,287

REFRIGERANT MOISTURE-LIQUID INDICATOR ASSEMBLY AND CAP UNIT THEREFORFiled Dec. 22, 1961 2 Sheets-Sheet 2 v y s 2@ /3 L 43 57 United StatesPatent 3,142,287 REFRIGERANT MOISTURE-LIQUID INDICATOR ASSEMBLY AND CAIUNlT TMREFOR Evan Jones, Evanston, Ill., assignor to Henry ValveCompany, Melrose Park, lll., a corporation of Illinois Filed Dec. 22,1961, Ser. No. 161,570 9 Claims. (Cl. 116-117) The invention is directedto a new and improved moisture .and/or liquid indicator assembly adaptedfor use in a refrigeration system for observance of liquid llow thereinand/or indication of change in moisture content of the refrigerant. Morespecifically, the invention is related directly to a new and improvedcap unit adapted for use as a moisture and/ or liquid indication meansand designed for removable application to suitable port means forming apart of a refrigeration system, the cap unit being of unique design andarrangement to include wholly contained moisture-liquid indication meanstherein for ready removal and application of the unit as a singleelement.

There are several different forms of moisture and/or liquid indicatorassemblies available at the present time for use in refrigerationsystems. Generally, these assemblies include a T section body portionhaving oppositely directed nipple-like port means for connection in arefrigerant flow line and further including a single radial port meanswhich has mounted therein or thereon a moistureliquid indicator unit.Liquid indication is often provided by means of a lensed window memberin spaced relation to an indicia carrying member which is inserted inthe body section for emersion in liquid iiow therethrough. Thepresenceof liquid counteracts the lensing effect of the window memberand the indicia is clearly observable through the window member.Moisture sensitive paper of known type also forms a part of the assemblyand is subject to color change when the moisture content of therefrigerant exceeds a predetermined level. Here again, the moisturesensitive paper is observable through the window member to note thecolor thereof.

The various elements of the type of moisture-liquid indicator unitdescribed above are loosely assembled in the radial port means andclamped therein by removable vbulls-eye-type closure means. The assemblyor disassembly of the unit requires individual handling of each of thevarious elements forming a part thereof and care must be taken duringassembly to place these elements in their proper relative positions toassure the establishment of a liquid-tight seal. Furthermore, variouselements of the unit, such as the moisture-senstive paper, rubbergaskets and the like, are often sensitive to heat which is applied tothe nipples of the T section as a result of brazing or sweatingoperations used during attachment of the T section to the refrigerantline. The standard practice is to completely remove all of the singleelements of the moisture-liquid indicator unit from the T section duringinstallation of the T section into a refrigerant line, and thenreassemble the unit to complete installation thereof. It is often thecase that the T section is installed in limited areas by necessity andit is quite difficult to individually handle and properly insert therelatively small separate elements of .the moisture-liquid indicationmeans following permanent attachment of the T section in the refrigerantline. Furthermore, it is often difficult to obtain an adequateliquid-tight seal during the iinal stages of complete installation dueto conditions of limited access to the indication means.

It is an object of the invention to provide a new and improvedrefrigerant moisture and/ or liquid indicator assembly including aunique cap unit therefor, the assembly and cap unit being of such designand arrangement to provide for ease of installation and final assemblythereof under conditions of limited access while additions 3,142,287lPatented `luly 28., 1964 ally providing for ready establishing andmaintaining of a liquid-tight seal.

A further object is to provide a new and improved moisture and/or liquidcap unit for ready application to and removal from a cap unit mountingpart of a refrigeration system, the unit being of such design andarrangement to eliminate the necessity of complete disassembly andreassembly of the various elements thereof, the unit further being of adesign to permit ready application to a refrigeration system with theminimum of effort required t0 establish and maintain a completeliquid-tight seal.

Other objects not specifically set forth will become apparent from thefollowing detailed description of the invention made in conjunction withthe accompanying drawings wherein:

FIG. 1 is a vertical section of one form of complete moisture-liquidindicator assembly of the present invention;

FIG. 2 is an exploded perspective of the various elements of the capunit of the assembly of FIG. 1, these elements being illustrated invertical section;

FIG. 3 is a vertical section of the cap unit of FIG. 1 illustratingcomplete assembly of the various elements thereof;

FIG. 4 is an end View of the assembly of FIG. 1 on reduced scale;

FIG. 5 is a plan view of the cap unit on reduced scale illustratingappearance of the same in the absence of liquid in the refrigerationsystem;

FIG. 6 is a view similar to FIG. 5 illustrating appearance of the capunit when the refrigeration system is filled with liquid;

FIG. 7 is a View similar to FIG. l illustrating a modi- `ied cap unitforming a part of the assembly;

FIG. 8 is a View similar to FIG. 2 illustrating the various elements ofthe modified cap unit of FIG. 7;

FIG. 9 is a view similar to FIG. 3 illustrating complete assembly of theelements of the modified cap unit;

FIG. 10 is a plan view of the cap unit of FIG. 9; and

FIG. 11 is an enlarged fragmentary section of a portion of the cap unitillustrating operational functioning of certain of the elements thereof.

Referring to FIG. 1, the assembly 10 includes a body member 11 in theform of a T section, it being understood that the invention is of ascope to include other means to which the cap unit 12 of the assembly 10may be removably attached in a refrigeration system. The body member 11illustrated includes a pair of oppositely directed nipple-like ports 13and 14 of known type adapted for brazing, sweating or soldering torefrigerant flow line sections to accommodate refrigerant flowtherethrough in the known manner. The internal passages of the ports 13and 14 are in communication with a central chamber 15 which in turn isin communication with an enlarged passageway 16 of a right angled,radially directed nipple-like port 17 integrally formed on the bodymember 1l. The outer surface of the projecting port 17 is formed withthreads 18 for removable attachment of the cap unit 12 thereon in endclosing relation.

As best illustrated in FIG. 2, the cap unit 12 comprises a tubular shell19 formed on the outer surface thereof with an enlarged hex head portion20 (FIG. 4) to permit ready application of a wrench or the like theretofor application or removal of the cap unit to the port 17 of the bodymember 11. The shell 19 includes an inner bore 21 of substantial axiallength which at the lower end thereof as Viewed is formed with threads22 for engagement with the threads 1S on the outer surface of the port17. The upper end of the bore 21 terminates in a radially inwardlydirected annular shoulder 23 which defines an upper stepped-in bore 24of substantially shorter axial length. The bore 24 terminates in Aaradially directed annular ange portion 25, the outer surface of which isush with the outer top end of the shell 19 and the inner edge 26 ofwhich defines an opening for use in observing the enlarged passageway 16in a manner to be described.

An annular gasket 27 formed from any suitable material, such as nylon,is dimensioned to be received in the reduced bore 24 in engagement withthe inner surface of the iiange 25 as shown in FIG. 3. A disc-likewindow member 28 formed from any suitable transparent material isdimensioned to be received in the reduced bore 24 with the peripheralportion of the upper face thereof in engagement with the gasket 27. Byreason of the provision of the shoulder 23 in the shell 19 and theenlarged bore 21 in association therewith, a substantial peripheralclearance is provided between the window member 2S and the bore 21. Inthis space a suitable O-ring seal 29 of known type is adapted to bereceived as best shown in FIG. 3, this seal performing the primaryfunction of proper spacing and positioning of the window member 28within the shell 19.

A second annular gasket 30 of the same type and dimensions as the gasket27 is received in the shell 19 in engagement with the peripheral portionof the bottom surface of the window member 2S in substantially spacedrelation to the bore 21. A flat ring of moisture sensitive paper 31 isreceived in engagement with the bottom surface of the gasket 30 and isprovided with the same outer diameter as the gasket 30 while having asmaller inner diameter to project substantially radially inwardly fromthe inner diameter of the gasket 30 and thus be readily viewed throughthe window member 28. A backup flat paper ring 32 of filter-type paperis combined with the moisture sensitive paper ring 31 and is of the samedimensions. The type of moisture sensitive paper suitable for use iswell known and is subject to color change in response to variation inrefrigerant moisture content below or above a predetermined level. Byway of example, the paper 31 may be of a blue color when the moisturecontent is below a predetermined level and may change to a pink colorwhen the moisture content of the refrigerant exceeds the predeterminedlevel.

A perforated support ring 33 formed from any suitable relatively rigidmaterial such as brass is of the same dimensions as the paper rings 31and 32 and is placed in supporting engagement therewith. Theperforations provided in the ring 33 permit the ow of refrigeranttherethrough into contact with the adjacent surfaces of the paper rings31 and 32 to completely wet the same. Furthermore, as previouslydescribed the paper rings 31 and 32 project radially inwardly beyond thegasket 30 into the passage 16 to an extent that refrigerant ow readilycontacts the same. The gasket 30 functions to space the moisturesensitive paper ring 31 from the adjacent surface of the window member28 as illustrated in FIG. 3 to provide for complete liquid contacttherewith for accurate moisture content indication.

The perforated support ring 33 has integrally formed therewith adepending leg portion 34 which extends downwardly away from the windowmember 28 into the passage 16 to a substantial extent. The lower portionof the leg portion 34 has suitably attached thereto a generally L-shapedindicia carrying plate member 35 which extends transversely across thepassage 16 for ready viewing of the top surface thereof through thewindow member 28. The top surface is provided with suitable indicia suchas the word FULL as illustrated. The bottom surface of the window member28 has formed centrally thereof a projecting convex lens portion 36 ofknown type which provides for magnification to an extent that theindicia on the member 35 is not observable through the window member 28when the passage 16 is empty of liquid as shown in FIG. 5. When liquidlls the passage 16 to an extent that the liquid actually surrounds thelens portion 36, the liquid eliminates the magnifica- '4 tion propertiesof the lens portion and the indicia on the member 35 is observablethrough the window member 28 as shown in FIG. 6.

The cap unit 12 is completed by the provision of a special annularpacking 37 of generally L-shape in cross section and formed with anaxially extending portion 38 and a radially inwardly extending portion39. The packing 37 is dimensioned to be snugly received in the bore 21of the shell 19 and the inner diameter 0f the axially extending portion3S is such that the same may become wedged between the periphery of thewindow member 28 and the adjacent surface of the bore 21 as shown inFIG. 3 to define a complete liquid tight seal about the window member2S. The top surface 40 of the radially directed portion 39 is in ahorizontal plane for engagement with the bottom surface of theperforated support ring 33 to clamp this ring and the rings 31 and 32and gasket 30 in assembled relation directly below the window member 28.The bottom surface 41 of the packing 37 including the bottom surfaceportion of the radially directed portion 39 is of frustoconical shapefor a purpose to be described.

The various elements described in FIG. 2 may be readily assembled in theshell 19 with the packing 37 functioning to frictionally hold the samein assembled relation therein. In this manner a complete and fullyassembled cap unit 12 is provided which may be readily applied to orremoved from the body member 11 without accompanying assembling ordisassembling of the individ ual elements forming a part of themoisture-liquid indication means. FIG. 3 illustrates the completelyassembled cap unit 12 when the same lis separated from the body member11. The packing 37 is dimensioned to be snuggly received in the shell 19to hold all of the various elements in their operative position. Thispacking may be formed from any suitable material, such aspolytetrauoroethylene which is inert to refrigerant and which is atleast partially self-lubricating to an extent that the same may bereadily inserted in the manner illustrated and yet establish sufficientfrictional engagement to maintain all of the various elements in theiroperative positions upon cap unit removal. The liquid indication meansincluding the member 35 actually forms an integral part of the cap unitand is not retained in the body member 11 upon cap unit removal. Thiscomplete assembly readily accommodates body member installation in arefrigerant line under elevated temperature `brazing or solderingconditions without attendant damage to moisture sensitive material orheat sensitive gaskets and the like.

The arrangement described is especially adapted for use in closecoupling situations where the area of access to the assembly 10 islimited. The installer merely removes the complete cap unit 12 from theassembly and installs the body member 11 in the easiest possible mannerWithout being concerned about heat damage to the sensitive elements ofthe cap unit. Upon completed installation of the body member 11, the capunit as a separate member can be readily applied to the port 17 withouthandling of the individual small elements thereof and without danger ofimproper assembly of these elements. This arrangement eliminates thenecessity of imposing limitations on the installer regarding temperaturelevels to be applied to the assembly such as in the case where the heatsensitive materials must be retained as a part of the assembly by reasonof the limited area available of access thereto. This arrangementfurther eliminates any need for the use of enlarged body members topermit heat application at distances sufficiently spaced from the heatsensitive elements to prevent damage thereto. Furthermore, thearrangement eliminates the individual handling of each of the variouselements of the moistureliquid indication means either prior to orsubsequent to installation of the assembly.

FIGS. l and 4 illustrate the use of the hex head outer surface portion20 of the cap unit 12 in retaining a pro tective cover cap 42 thereon.This cover cap is preferably formed from flexible plastic material whichis readily expanded over the hex head surface portions to cover the topof the cap unit 12 and protect the window member 2S from damage or theaccumulation of dirt on the top surface thereof.

Referring particularly to FIG. 1, the top edge of the port 17 ispreferably formed with a frusto-conical surface 43 which correspondswith the bottom surface 41 of the packing 37. Upon application of thecap unit 12 to the port 17 and threaded advancement thereof, thefrustoconical surface 43 engages the similar surface of the packing 37and moves the same in the bore 21 of the shell 19 in such a manner thatthe axially extending portion 38 thereof moves upwardly into tightsealing relation between the Window member 28 and the bore 21 and theother Various elements are pressed into tight engagement with the windowmember. Furthermore, the top peripheral edge portion of the windowmember 28 is pressed into tight engagement with the gasket 27 thusproviding a completely liquid-tight seal. In this respect, it will benoted that the axially extending portion 3S of the packing 37 extendssubstantially upwardly in overlapping relation with the periphery of thewindow member 28 to provide a complete seal about the bottom edgethereof. The O-ring seal 29 functions primarily to maintain propercentering of the window member 28 in the shell 19. The gaskets 27 and 3@not only provide for the establishing and maintaining of a liquid-tightseal, but also function to prevent damage to the window member 28 duringtightening of the cap unit 12 on the body member 11. Furthermore, thegasket 30 maintains the moisture sensitive paper ring 31 in spacedrelation to the bottom surface of the window unit for proper liquidcontact therewith during use of the assembly. With the arrangementdescribed involving the particular design and arrangement of the packing37, during tightening of the cap unit 12 on the body member 11 noexcessive torque is exerted on any single seal or element of the capunit. It has been found that by reason of this particular arrangement,the cap unit 12 may be readily tightened on the port 17 for liquid-tightsealing relation merely by a 1/2 turn or the like and that suchtightening can be obtained readily by hand. It will be appreciated thatthis advantage is of substantial use in close coupling stiuationsinvolving areas of limited access.

FIGS. 7-ll illustrate a slightly modified form of the cap unit 12described above. The modified cap unit in these views is identified bythe numeral 44 but certain elements forming a part thereof, which arebasically the same as the elements previously described, are identifiedby the same reference numerals. The cap unit 44 is intended basicallyfor use as a moisture indication means 4and does not include theadditional liquid indication means previously described. In this respectthe cap unit includes a plain glass window member 45 not provided withthe lens portion previously described and the perforated support ring 46thereof is a plain fiat ring not including the depending leg portion forliquid indication means attachment thereto as previously described. Inall other respects the cap unit 44 is identical with the cap unit 12 andthe relatively minor differences are indicative of additionaladvantageous aspects of the basic concept of the invention. In thisregard, it will be appreciated that the unique combination of elementsin the basic cap unit design of the invention involves the use of anumber of similar parts for both moisture and liquid indication. Thus,the supplier need merely stock these basic parts with the same beinguseful for either moisture or liquid indication or the combination ofthe two as required by customers. It is necessary merely to substitutein the cap unit either the window members 28 or 4S and the perforatedsupport means 33 or 46 as required. In all other respects, the elementsare identical and the substitution may be readily accomplished.

FIGS. 7 and 1l illustrate another important aspect of the cap unitdesign which has been briefly mentioned above. As previously described,the moisture sensitive and back-up paper rings 31 and 32 extendsubstantially radially inwardly beyond the inner diameters of theassociated gasket 30 and radially extending portion 39 of the packing37. The perforated support ring also extends radially inwardly to thesame extent to adequately support the inner peripheral portions of thepaper rings. However, by reason of the perforations in the support ringliquid is permitted to flow therethrough into contact with the paperrings and these rings may actually be lifted to the extent illustratedin FIGS. 7 and l1. Freedom of movement of the inner peripheral portionsof the paper rings to the extent illustrated further accommodatescomplete liquid contact therewith for efiicient moisture contentindication. There is no danger of displacement of the paper rings byreason of the cooperating clamping action provided by the gasket Sil andpacking 37. For ready moisture content determination, the top flatsurface of the shell 1.9 may have applied thereto a ring label 47 whichas best shown in FIG. l0 may on one-half thereof include the pink colorwith an adequate reminder to indicate that this color indicatesexcessive moisture content, and the other half thereof including a bluecolor to indicate that this color appearing in the moisture sensitivepaper ring 3l assures proper moisture content level.

Obviously certain modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and therefore only such limitations should be imposed asare indicated in the appended claims.

I claim:

l. A moisture indicator cap unit for removable application to a Tsection of a refrigerant flow line, said cap unit comprising a tubularshell having received therein a window member of a diameter less thanthe inner diameter of said shell, an annular packing of generallyL-shaped cross section in said shell and including an axially directedportion compressibly fixed between the periphery of said window memberand said shell and retaining said window member in said shell, saidpacking further including a radially inwardly directed portion overlyingthe marginal area of the inner face of said window member and arrangedfor outer radial surface sealing engagement with a T section surfaceupon application of said cap unit, and moisture sensitive meansresiliently held between the radially directed portion of said packingand the marginal area of said inner face of said window member forobservance through said window member.

2. A moisture-liquid indicator cap unit for removable application to a Tsection of a refrigerant flow line, said cap unit comprising a tubularshell having received therein a window member of a diameter less thanthe inner diameter of said shell, an annular packing of generallyL-shaped cross section in said shell and including an axially directedportion compressibly fixed between the periphery of said window memberand said shell and retaining said window member in said shell, saidpacking further including a radially inwardly directed portion overlyingthe marginal area of the inner face of said window member, moisturesensitive means resiliently held between the radially directed portionof said packing and the marginal area of said inner face of said windowmember for observance through said window member, and liquid indicationmeans resiliently held between the radially directed portion of saidpacking and the marginal area of said inner face of said window memberand projecting from said window member through said packing axially ofsaid shell, said liquid indication means terminating in a transverselyextending indicia carrying portion in spaced relation from said windowmember, said window member including a lens portion centrally thereofadapted to pro- Vide for observance of the indicia of said liquidindica- J tion means through said window member when said T section isfilled with liquid.

3. A moisture indicator assembly for use in a refrigeration system, saidindicator assembly comprising a body member including first and secondport means, said first port means being adapted for connection with arefrigerant flow line in communication therewith, said second port meansincluding a removable moisture indicator cap unit received thereon, saidcap unit comprising a tubular shell having received therein a windowmember of a diameter less than the inner diameter of said shell, anannular packing of generally L-shaped cross section in said shell andincluding an axially directed portion compressibly fixed between theperiphery of said window member and said shell and retaining said windowmember in said shell, said packing further including a radially inwardlydirected portion overlying the marginal area of the inner face of saidwindow member, and moisture sensitive means resiliently held between theradially directed portion of said packing and the marginal area of saidinner face of said window member for observance through said windowmember, said second port means including a top annular edge portion offrusto-conical shape engaged with the outer surface of the radiallydirected portion of said packing, said outer packing surface being ofcorresponding frusto-conical shape to provide for wedging of saidpacking in said shell about said window member to establish aliquid-tight seal.

4. A moisture-liquid indicator assembly for use in a refrigerationsystem, said indicator assembly comprising a body member including firstand second port means, said first port means being adapted forconnection with a refrigerant fiow line in communication therewith, saidsecond port means including a removable moisture indicator cap unitreceived thereon, said cap unit comprising a tubular shell havingreceived therein a window member of a diameter less than the innerdiameter of said shell, an annular packing of generally L-shaped crosssection in said shell and including an axially directed portioncompressibly fixed between the periphery of said window member and saidshell and retaining said window member in said shell, said packingfurther including a radially inwardly directed portion overlying themarginal area of the inner face of said window member, moisturesensitive means resiliently held between the radially directed portionof said packing and the marginal area of said inner face of said windowmember for observance through said window member, and liquid indicationmeans resiliently held between the radially directed portion of saidpacking and the marginal area of said inner face of said window memberand projecting from said window member through said packing axially ofsaid shell, said liquid indication means terminating in a transverselyextending indicia carrying portion in spaced relation from said windowmember, said window member including a lens portion centrally thereofadapted to provide for observance of the indicia of said liquidindication means through said window member when said assembly is filledwith liquid, said second port means including a top annular edge portionof frusto-conical shape engaged with the outer surface of the radiallydirected portion of said packing, said outer packing surface being ofcorresponding frusto-conical shape to provide for wedging of saidpacking in said shell about said window member to establish aliquid-tight seal.

5. A moisture indicator assembly for use in a refrigeration system, saidindicator assembly comprising a body member including first and secondport means, said first port means being adapted for connection with arefrigerant flow line in communication therewith, said second port meansincluding a removable moisture indicator cap unit received thereon, saidcap unit comprising a tubular shell which at the outer end thereof isformed with an annular radially inwardly directed flange, a first gasketin said shell in engagement with said fiange, a Window member in saidshell with the marginal area of the outer surface thereof in engagementwith said first gasket, said window member being of a diameter which isless than the inner diameter of said shell, an O-ring seal about theperiphery of said window member to center the same in said shell, asecond gasket in said shell in engagement with the inner surface of saidwindow member, annular moisture sensitive means in engagement with saidsecond gasket, perforated support means in engagement with said moisturesensitive means, and a generally L-shaped annular packing in said shell,said packing comprising an axially extending portion received about saidsupport means, moisture sensitive means, second gasket and a portion ofthe outer periphery of said window member, and a radially inwardlyextending portion overlapping and in engagement with said support means,said packing being compressibly fixed in said shell and cooperating withsaid flange of said shell to retain the aforesaid elements therebetweenupon removal of said cap unit from said assembly.

6. A moisture indicator assembly for use in a refrigeration system, saidindicator assembly comprising a body member including first and secondport means, said first port means being adapted for connection with arefrigerant flow line in communication therewith, said second port meansincluding a removable moisture indicator cap unit received thereon, saidcap unit comprising a tubular shell which at the outer end thereof isformed with an annular radially inwardly directed frange, a first gasketin Said shell in engagement with said fiange, a window member in saidshell with the marginal area of the outer surface thereof in engagementwith said first gasket, said window member being of a diameter which isless than the inner diameter of said shell, an O-ring seal about theperiphery of said window member to center the same in said shell, asecond gasket in said shell in engagement with the inner surface of saidwindow member, annular moisture sensitive means in engagement with saidsecond gasket, perforated support means in engagement with said moisturesensitive means, and a generally L-shaped annular packing in said shell,said packing comprising an axially extending portion received about saidsupport means, moisture sensitive means, second gasket and a portion ofthe outer periphery of said window member, and a radially inwardlyextending portion overlapping and in engagement with said support means,said packing being compressibly fixed in said shell and cooperating withsaid fiange of said shell to retain the aforesaid elements therebetweenupon removal of said cap unit from said assembly, said moisturesensitive means projecting inwardly beyond said second gasket for readyobservance thereof through said window member.

7. A moisture indicator assembly for use in a refrigeration system, saidindicator assembly comprising a body member including first and secondport means, said first port means being adapted for connection with arefrigerant flow line in communication therewith, said second port meansincluding a removable moisture indicator cap unit received thereon, saidcap unit comprising a tubular shell which at the outer end thereof isformed with an annular radially inwardly directed flange, a first gasketin said shell in engagement with said flange, a window member in saidshell with the marginal area of the outer surface thereof in engagementwith said first gasket, said window member being of a diameter which isless than the inner diameter of said shell, an O-ring seal about theperiphery of said Window member to center the same in said shell, asecond gasket in said shell in engagement with the inner surface of saidwindow member, annular moisture sensitive means in engagement with saidsecond gasket, perforated support means in engagement with said moisturesensitive means, and a generally L-shaped annular packing in said shell,said packing comprising an axially extending portion received about saidsupport means, moisture sensitive means, second gasket and a portion ofthe outer periphery of said window member, and a radially inwardlyextending portion overlapping and in engagement with said support means,said packing being compressibly ixed in said shell and cooperating withsaid ilange of said shell to retain the aforesaid elements therebetweenupon removal of said cap unit from said assembly, said second port meansincluding a top annular edge portion of frusto-conical shape engagedwith the outer surface of the radially inwardly extending portion ofsaid packing, said outer packing surface being of correspondingfrusto-conical shape to provide for wedging of said packing in saidshell about the aforesaid elements therein to establish a liquid-tightseal.

8. A moisture-liquid indicator assembly for use in a refrigerationsystem, said indicator assembly comprising a body member including iirstand second port means, said rst port means being adapted for connectionwith a refrigerant flow line in communication therewith, said secondport means including a removable moisture indicator cap unit receivedthereon, said cap unit comprising a tubular shell which at the outer endthereof is formed with an annular radially inwardly directed tlange, afirst gasket in said shell and in engagement with said flange, a windowmember in said shell with the marginal area of the outer surface thereofin engagement with said first gasket, said Window member being of adiameter which is less than the inner diameter of said shell, an O- ringseal about the periphery of said window member to center the same insaid shell, a second gasket in said shell in engagement with the innersurface of said window member, an annular moisture sensitive means inengagement with said second gasket, perforated support means inengagement with said moisture sensitive means, and a generally L-shapedannular packing in said shell,

said packing comprising an axially extending portion received about saidsupport means, moisture sensitive means, second gasket and a portion ofthe outer periphery of said window member, and a radially inwardlyextending portion overlapping and in engagement with said support means,said packing being compressibly ixed in said shell and cooperating withsaid flange of said shell to retain the aforesaid elements therebetweenupon removal of said cap unit from said assembly, said support meansincluding a leg portion projecting axially of said shell through saidpacking away from said Window member and terminating in a transverselyextending indicia carrying portion, said window member including a lensportion centrally thereof adapted to provide for observance of theindicia through said window member when said assembly in filled withliquid.

9. The moisture-liquid indicator assembly of claim 8 wherein said secondport means includes a top annular edge portion of frusto-conical shapeengaged with the outer surface of the radially inwardly extendingportion of said packing, said outer packing surface being ofcorresponding frusto-conical shape to provide for wedging of saidpacking in said shell about the aforesaid elements therein to establisha liquid-proof seal.

References Cited in the iile of this patent UNITED STATES PATENTS2,716,338 Blinn Aug. 30, 1955 2,787,238 Luce Apr. 2, 1957 2,844,026Wischmeyer July 22, 1958 2,933,060 Yocum Apr. 19, 1960 3,000,345 GraySept. 19, 1961 3,088,811 Jones May 7, 1963

1. A MOISTURE INDICATOR CAP UNIT FOR REMOVABLE APPLICATION TO A T SECTION OF A REFRIGERANT FLOW LINE, SAID CAP UNIT COMPRISING A TUBULAR SHELL HAVING RECEIVED THEREIN A WINDOW MEMBER OF A DIAMETER LESS THAN THE INNER DIAMETER OF SAID SHELL, AN ANNULAR PACKING OF GENERALLY L-SHAPED CROSS SECTION IN SAID SHELL AND INCLUDING AN AXIALLY DIRECTED PORTION COMPRESSIBLY FIXED BETWEEN THE PERIPHERY OF SAID WINDOW MEMBER AND SAID SHELL AND RETAINING SAID WINDOW MEMBER IN SAID SHELL, SAID PACKING FURTHER INCLUDING A RADIALLY INWARDLY DIRECTED PORTION OVERLYING THE MARGINAL AREA OF THE INNER FACE OF SAID WINDOW MEMBER AND ARRANGED FOR OUTER RADIAL SURFACE SEALING ENGAGEMENT WITH A T SECTION SURFACE UPON APPLICATION OF SAID CAP UNIT, AND MOISTURE SENSITIVE MEANS RESILIENTLY HELD BETWEEN THE RADIALLY DIRECTED PORTION OF SAID PACKING AND THE MARGINAL AREA OF SAID INNER FACE OF SAID WINDOW MEMBER FOR OBSERVANCE THROUGH SAID WINDOW MEMBER. 